Many devices today have the capability of operating from one or more different power sources. For example, mobile phones can operate on battery power or from an AC outlet. Transition between these various power sources can be difficult because the switch-over can create current spikes or relatively large in-rush currents. There have been various proposed circuit to adjust for in-rush currents. Some examples conventional circuits are U.S. Pat. Nos. 6,333,623; 6,559,623; 6,867,640; 6,977,491; 7,233,462; and 7,315,154.